Liquid helium distribution system



Feb. 20, 1968 J. KLEINHAUT ET AL Original Filed May IL 1966 L/QU/D HELlUM a a i k/ v PS I F' 20 8 (22 0 [VAPOR/25R ICOMPRESSOR' L/QU/D A 2CYLINDER I 5 6 F/LL i V d TO 40 CUSTOMER INVENTORS JOSEPH KLElNHAUT MARKM. LEE ARNO RA AG ATTORNEY United States Patent OfiFice 3,369,372Patented F ab. 20, 1968 3,369,372 LIQUID HELIUM DISTRIBUTION SYSTEMJoseph Kleinhaut, Livingston, Mark M. Lee, North Bergen, and Arno Raag,West New York, N.J.,

assignors to Air Reduction Company, Incorporated, New York, N.Y., acorporation of New York Continuation of application Ser. No. 550,751,May 17, 1966. This application Apr. 17, 1967, Ser. No. 631,550 14Claims. (Cl. 62--52) ABSTRACT OF THE DISCLOSURE An apparatus and processfor the eflicient handling of liquid helium supplied to a demand ineither liquid or gaseous form through a simple and efiicientdistribution system in a manner so as to minimize losses.

This application is a continuation of application No. 550,751, filed May17, 1966, now abandoned.

The present invention relates to the eflicient handling and delivery ofhelium.

More particularly, the present invention relates to the efficienthandling of liquid helium supplied to a customer in either liquid or gasform through a unique distribution system in a manner so as to minimizelosses.

Helium is a relatively expensive. product. In the past, when it has hadto be distributed over relatively long distances, it has beentransported in gaseous form. Transportation of helium in liquid form hasnecessitated an elaborate and expensive recovery system. However, it isadvantageous to transport helium in liquid form since larger quantitiescan be transported per truck full of liquid than gas, makingtransportation of this rare gas more economical, especially since theliquid can easily be transformed into gas while still having acapability of supplying the liquid user with his requirements.

The difiiculty in the past has been in designing an efficient system fordistributing the helium so that losses of helium in the handling of thehelium would be substantially eliminated, while not requiringencumbering capital investment for complicated apparatus to insuremaximum recovery of the helium. Contamination of the helium liquid orgas to which it is transformed also must be insured against.

It is therefore an object of this invention to design a distributionsystem for use with a liquid helium transport and/or storage containerwhich allows for both helium liquid and helium gas recovery with aminimum of losses in handling.

It is a further object of this invention to provide a simple andeflicient system for supplying helium from a vessel. 7

More specifically, it is further an object of this invention to providea simple and efficient system for supply- I ing, with minimum losses,either liquid or gaseous helium from a movable liquid helium trailersource to a customer.

Other objects and advantages of this invention will become more apparentupon reading the following more detailed disclosure.

As previously stated, helium is a relatively expensive product. Thephilosophy in setting up a helium distribution system is at all times tominimize helium losses in handling. Helium is produced in relatively fewlocations spread relatively far apart. It is not uncommon to transporthelium many hundreds of miles before it is supplied to the customer.

The system for supplying helium to be described hereinafter is to beused, for example, with a liquid helium trailer source, usually one thathas transported the helium to the point of distribution. It isemphasized that it is intended that said system may be utilized withstationary liquid helium tanks as well as transportable trailers. Thetrailer vessel carrying the liquid helium may be used for example bothfor transport of the liquid helium and to store it at a distributionterminal.

Throughout the specification which follows, applicants will refer toliquid helium storage with a liquid and gas phase. It is understood,however, that this terminology embraces storage in the trailer orstorage vessel of helium under pressure conditions which either (1) makethe helium contained therein of a single phase; or (2) allow heliumcontained therein to be in the two-phase condition.

Generally speaking, the distribution system which is the subject of ourinvention provides for liquid filling from the trailer or storage vesselto a smaller (as compared to the trailer) customer liquid storagecontainer, sometimes called a dewar. That liquid filling and gas supply,which is believed to be the major customer consideration, is suppliedgenerally in the following manner.

Gas (or single phase helium, in the case of single phase storage)supplied from the upper portion of the liquid helium trailer or storagevessel is supplied through a vaporizer and compressor to the gascustomer. At times, liquid is withdrawn from the trailer orstoragevessel, vaporized to gas, and then compressed before beingsupplied to a customer. Flash gas evolving from the liquid filling ofsaid smaller liquid container combines with the helium supplied from thetrailer or storage vessel for compression into warm helium gascontainers or supply of other customer demand. If the pressure intheliquid helium storage container falls below a certain pressure limit,then liquid helium is withdrawn from the trailer or vessel andefiiciently vaporized and supplied back as gas into the liquid heliumtrailer or vessel in order to raise the pressure.

This system will now be described in more detail in relation to theaccompanying drawing, which shows in schematic form the distributionsystem which is the subject of this invention.

Referring to the drawing, a helium source, hereafter called a vessel,which may be, for example, a transportable trailer or a storage vessel,is shown at 1. That vessel 1 supplies liquid helium through a liquiddischarge line 3 to smaller containers for customer use, said smallercontainers being shown at 2. A second liquid discharge line 4 directsliquid helium from the vessel 1 through a helium discharge line 40, andthen to a vaporizer 5 (to superheat it) and a compressor 6, and then toa customer as shown in the drawing. A third discharge line 7 extendsfrom the upper part of the helium vessel ii and is in con nection withthe discharge line 40 previously described, and then to the vaporizer 5,compressor 6, and customer. The discharge line 7 conducts gas (or highdensity single phase cold helium if that is in fact what the heliumsource contains, as discussed previously) from the upper part of thevessel 1 to the discharge line 40 and then to the vaporizer. Aconnecting line 8 transports flash vapor evolved from the filling of theliquid cylinders 2 to the discharge line 4 (or alternatively, but notshown, directly to the discharge line 40) for supply to the customer.

The pressure in vessel 1, for example about 3 to 5 p.s.i.g., will supplyliquid to the liquid cylinder 2 when valve 20 is open. The higher thetrailer pressure, the more flash vapor will be generated for a giventransfer of helium liquid from the vessel 1 to the cylinder 2. Thecompressor 6 is maintained at a compressor suction of only a few inchesof water above the atmospheric so as not to create an excessive backpressure in the smaller liquid helium cylinders 2. This compressorsuction pressure, however, will insure against air leakage into thesystem. Flash vapor which does evolve from the filling of the cylinder 2is recovered through line 8.

Gas will be withdrawn from the vessel 1 through a valve 11. The actionof the valve 11 may be manually controlled or alternatively controlledby a pressure control device 21. Upon the opening of valve 11, gas fromthe vessel 1 is supplied through the line 7 to the supply line 40, thevaporizer 5, the compressor 6, and then to the customer demand. A secondgas removal line 9 from the container 1 is provided only to be utilizedin emergency situations to keep the trailer 1 within the maximumpressure safety limit prescribed. Flow through said line 9 may becontrolled through a standard safety valve shown, for example, at 22.

If vapor flow through line 7 and/or line 8, while the liquid is beingsupplied to the cylinder 2, is not suflrcient to supply the compressorsuction, then a pressure control mechanism 10 monitoring the flow inline 40 will operate to open line 4 through the valve 12 in order toaugment the flow requirement. Again, the operation of valve 12 mayalternatively be manual. Liquid supplied through valve 12 is vaporizedin the line or in the vaporizer (depending on conditions) compressed to,for example, about 3000 psig. in the compressor 6, and supplied to thecustomer.

If the pressure in the vessel 1 falls below a certain minimum limit, forexample about 3 p.s.i.g., below which the flow rate in the system isdiminished, a valve 13 responsive to a pressure control device 14,monitoring pressure conditions within the trailer (valve 13alternatively may be manually controlled) will open in order to rerouteat least a portion of the helium in line 4 derived from the trailer backthrough the line 7 into the vessel 1 as a gas, in order to raise thepressure above the minimum level. The helium will vaporize beforereaching the vessel 1, and such vaporization can be abetted by the useof a heat exchanger, not shown.

The vaporizer 5 may be of any chosen design, for ex- :ample a hot Watervaporizer with an electric heater used .as the heat source. Thecompressor 6 may also be of any desired design, preferably anonlubricating machine capable of compressing helium gas fromatmospheric pres- ;sure to at least 3000 p.s.i.g.

None of the details of the process or apparatus described above or shownin the drawing should be construed so as to limit applicants invention.Rather applicants invention should be limited only by the scope of thefollowing claims.

We claim:

1. A process for the eflicient supply of helium from a vessel to meet ademand comprising the steps of supplying helium in gaseous form fromsaid vessel, supplying liquid helium from said vessel when the gassupplied does not satisfy said demand, passing said helium suppliedthrough a vaporizer to vaporize and superheat it, compressing the heliumafter passing it through the vaporizer, directing the compressed,vaporized heated helium to the demand, and returning helium suppliedfrom the vessel in liquid form back to the vessel in gaseous form whenthe pressure in the vessel falls below a minimum pressure limit.

2. A process as set forth in claim 1, further comprising the steps offilling a small container with liquid helium supplied from the vessel,drawing flashed vapor from said liquid filling, and combining saidflashed vapor with said helium to be passed through said vaporizer.

3. A process as set forth in claim 2, further comprising the steps ofcontrolling the quantity of supply of liquid helium from the vesseldirected to the vaporizer in relation to the quantity of vaporcontemporaneously drawn from the filling of the container and suppliedfrom the vessel.

4. A process as set forth in claim 3, the minimum pressure limit beingabout 3 p.s.i.g.

5. Apparatus for the eflicient supply of helium from a vessel comprisingvaporizing means, compressing means, means connecting the vaporizingmeans to the compressing means, means for supplying helium as a gas fromthe compressing means to meet a demand, means connecting said vessel tomeans leading to said vaporizing means for directing liquid from saidvessel to said vaporizing means, additional means connecting said vesselto said means leading to said vaporizing means for directing gas fromsaid vessel to said vaporizing means, valve means for controllingmovement of gas from said vessel into said means for directing gas, andadditional valve means for directing liquid, taken from the vessel inthe means for directing liquid, back to the vessel in the form of gaswhen the pressure within the vessel falls below a minimum pressurelimit.

6. Apparatus as claimed in claim 5, further comprising pressureresponsive means responsive to the pressure within the vessel to opensaid additional valve means when said pressure falls below said minimumpressure limit.

7. Apparatus as claimed in claim 6, further comprising means fordelivering liquid from said vessel to a container, means fortransporting substantially all flashed vapor from said last-mentionedliquid delivery means and said container to said means leading to saidvaporizing means.

8. Apparatus as claimed in claim 7, further comprising still additionalvalve means for controlling the quantity of liquid directed from thevessel to the means leading to the vaporizer, and pressure responsivemeans for actuating said last-mentioned valve means upon monitoring thesupply of flashed vapor from the small container plus from the gasdirecting means.

9. Apparatus as claimed in claim 5, further comprising additionalpressure responsive means dependent on the pressure in said vessel foractuating the first-mentioned valve means.

19. Apparatus as claimed in claim 6, the minimum pressure limit beingabout 3 p.s.i.g.

11. A process for the eflicient supply of helium from a vessel to meet ademand comprising the steps of supplying helium in gaseous form fromsaid vessel, supplying liquid helium from said vessel when the gassupplied does not satisfy said demand, passing said helium suppliedthrough a vaporizer to vaporize and superheat it, compressing the heliumafter passing it through the vaporizer, directing the compressed,vaporized heated helium to the demand, filling a container with liquidhelium supplied from the vessel, drawing flashed vapor from said liquidfilling, and combining said flashed vapor with said helium to be passedthrough said vaporizer and controlling the euantity of liquid heliumsupplied from the vessel and directed to the vaporizer in relation tothe quantity of vapor contemporaneously drawn from the filling of thecontainer and supplied from the vessel.

12. Apparatus for the efficient supply of helium from a vesselcomprising vaporizing means, compressing means, means connecting thevaporizing means to the compressing means, means for supplying helium asa gas from the compressing means to meet a demand, means connecting saidvessel to means leading to said vaporizing means for directing liquidfrom said vessel to said vaporizing means, additional means connectingsaid vessel to said means leading to said vaporizing means for directinggas from said vessel to said vaporizing means, valve means forcontrolling movement of gas from said vessel into said additional means,means for delivering liquid from said vessel to a container, means fortransporting substantially all flashed vapor from said last-mentionedliquid delivery means and said container to said means leading to saidvaporizing means, valve means for controlling the quantity of liquiddirected from the vessel to the means leading to the vaporizing means,and pressure responsive means for actuating said last-mentioned valvemeans when the pressure in the means leading to the vaporizing meansdrops below a desired minimum pressure.

13. A process for the efficient supply of helium from a vessel to meet ademand comprising the steps of supplying helium in gaseous form fromsaid vessel, supplying liquid helium from said vessel when the gassupplied does not satisfy said demand, passing said helium suppliedthrough a vaporizer to vaporize and superheat it, compressing the heliumafter passing it through the vaporizer, directing the compressed,vaporized heated helium to the demand, filling a container With liquidhelium supplied from the vessel, drawing flashed vapor from said liquidfilling, utilizing said flashed vapor to at least partially meet thedemand.

14. A process as set forth in claim 11, further comprising, maintainingthe pressure in the vessel above a minimum pressure limit by returninggaseous helium to the vessel When the pressure in the vessel falls belowthe minimum pressure limit.

References Cited LLOYD L. KING, Primary Examiner.

